Imaging range finder fabrication

ABSTRACT

Fabrication of an imaging range finder is disclosed. The range finder can be formed of an imaging lens and an array of emitters and photodetectors in optical communication with the lens. The emitters in the array can be formed to emit light that is directed by the lens toward a target object. The photodetectors in the array can be formed to detect light received from the object through the lens and onto the photodetectors. The lens, the array, or both can be movable to adjust the light emitted by the range finder. The range finder can be formed to find the object&#39;s range based on characteristics of the emitted light and/or the detected light.

FIELD

This relates generally to range finders and more specifically tofabrication of range finders integrated with imaging technology.

BACKGROUND

Range finders are very popular devices for determining a proximate rangeor distance of a target object. One type is a camera-based range finder,which projects a field of spots onto the target object and captures animage of the spots with a remote camera. The range finder uses theparallax shift of the spots in the captured image to determine theobject's range. The greater the parallax shift, the closer the object.However, the image resolution of the spots can be very poor for farobjects, such that the range finder is limited to use with near objects.

Another type is an intensity-based range finder, which blasts fullvisible light toward the target object and captures the light the objectreflects back. The range finder uses the intensity of the reflectedlight to determine the object's range. The dimmer the intensity, thefarther the object. However, different colors can reflect differentintensities, such that different-colored objects at the same range canreflect different light intensities. Similarly, if the range finder hasdirt, smudges, or other particles on it, these particles can block someof the reflected light, thereby dimming the intensity of the reflectedlight to make the object appear farther away than it is. Or theseparticles can themselves reflect back light emitted by the range finder,thereby brightening the intensity of the reflected light to make theobject appear closer than it is. Also, this range finder is generallylimited to use with very close objects, e.g., on the order ofmillimeters.

A third type is a time-of-flight range finder, which emits a light pulseand detects a pulse reflected back from the target object. The rangefinder uses the phase shift between the emitted and reflected pulses andthe speed of light to determine the time lapse between the pulses. Thegreater the time lapse, the farther the object. However, there areseveral issues with this range finder. It can be power inefficient. Theemission wavelengths can interfere with the retina of the human eye,raising eye safety concerns. And the resolution can be low to moderate,making object detection less accurate.

Accordingly, currently available range finders often do not provide thedesirable accuracy and performance that many applications require.

SUMMARY

This relates to fabricating an imaging range finder that can include animaging lens and an array of emitters and photodetectors in opticalcommunication with the lens. The emitters in the array can be formed toemit light onto the lens. The lens can be formed adjacent to the arrayto then direct the light from the emitters toward a target object. Thephotodetectors in the array can be formed to detect light from theobject received through the lens and onto the photodetectors. In someinstances, the array can be movable using an electromechanical devicecoupled thereto so as to adjust the angle of the emitted light. In someinstances, the lens can be movable using an electromechanical devicecoupled thereto so as to adjust the angle of the light passing throughthe lens. In some instances, a second movable lens can be added adjacentto the first movable lens. In some instances, both the lens and thearray can be movable. In some instances, a prism can be disposed betweenthe lens and the array and movable using an electromechanical devicecoupled to the prism so as to adjust the apparent source of the emittedlight. The imaging range finder can advantageously provide near- andfar-distance object detection accuracy in a power saving and eye safemanner and in less ideal and variable object and environment conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an imaging range finder having a fixed array and lensaccording to various examples of the disclosure.

FIGS. 2A through 2C illustrate a combined emitter-photodetector arrayfor an imaging range finder according to various examples of thedisclosure.

FIG. 3 illustrates driver circuitry for the imaging range finder of FIG.1 according to various examples of the disclosure.

FIGS. 4A through 4D depict light paths for the imaging range finder ofFIG. 1 according to various examples of the disclosure.

FIGS. 5A through 5F illustrate operating modes of an imaging rangefinder according to various examples of the disclosure.

FIGS. 6A through 6D illustrate fabrication of the imaging range finderof FIG. 1 according to various examples of the disclosure.

FIG. 7 illustrates an imaging range finder having a movable prismaccording to various examples of the disclosure.

FIGS. 8A through 8E depict light paths for the imaging range finder ofFIG. 7 according to various examples of the disclosure.

FIG. 9 illustrates driver circuitry for the imaging range finder of FIG.7 according to various examples of the disclosure.

FIGS. 10A through 10E illustrate fabrication of the imaging range finderof FIG. 7 according to various examples of the disclosure.

FIG. 11 illustrates an imaging range finder having a movable arrayaccording to various examples of the disclosure.

FIGS. 12A and 12B depict light paths for the imaging range finder ofFIG. 11 according to various examples of the disclosure.

FIG. 13 illustrates driver circuitry for the imaging range finder ofFIG. 11 according to various examples of the disclosure.

FIGS. 14A through 14E illustrate fabrication of the imaging range finderof FIG. 11 according to various examples of the disclosure.

FIG. 15 illustrates an imaging range finder having a movable imaginglens according to various examples.

FIGS. 16A and 16B depict light paths for the imaging range finder ofFIG. 15 according to various examples of the disclosure.

FIGS. 17A through 17F illustrate fabrication of the imaging range finderof FIG. 15 according to various examples of the disclosure.

FIG. 18 illustrates an imaging range finder having a movable array and amovable imaging lens according to various examples of the disclosure.

FIG. 19 illustrates an imaging range finder having multiple movableimaging lenses according to various examples of the disclosure.

FIG. 20 illustrates a lens portion of an imaging range finder havingmultiple imaging lenses according to various examples of the disclosure.

FIG. 21 depicts light paths for the imaging range finder of FIG. 20according to various examples of the disclosure.

FIG. 22 illustrates a computing system having an imaging range finderaccording to various examples of the disclosure.

FIG. 23 illustrates a mobile telephone that can include an imaging rangefinder according to various examples of the disclosure.

FIG. 24 illustrates a digital media player that can include an imagingrange finder according to various examples of the disclosure.

FIG. 25 illustrates a portable computer that can include an imagingrange finder according to various examples of the disclosure.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanyingdrawings in which it is shown by way of illustration specific examplesof the disclosure that can be practiced. It is to be understood thatother examples can be used and structural changes can be made withoutdeparting from the scope of the various examples of the disclosure.

This relates to fabrication of an imaging range finder that can includean array of emitters and photodetectors in optical communication with animaging lens. The emitters can be formed to emit light onto the lens.The lens can be formed to then direct the light toward a target object.The photodetectors can be formed to detect light from the objectreceived through the lens and onto the photodetectors. In some examples,the light received from the object can be the range finder's emittedlight reflected back from the object. In some examples, the lightreceived from the object can be light generated by the object itself. Insome examples, the light received from the object can be light generatedexternal to both the range finder and the object and reflected from theobject.

In some examples, the array and the lens can be fixed in place. In someexamples, the array can be movable using an electromechanical devicecoupled to the array so as to adjust the angle of the emitted light. Insome examples, the lens can be movable using an electromechanical devicecoupled to the lens so as to adjust the angle of the light passingthrough the lens. In some examples, a second movable lens can be addedadjacent to the first movable lens. In some examples, both the lens andthe array can be movable. In some examples, a movable prism can bedisposed between the lens and the array and rotated or tilted using anelectromechanical device coupled to the prism so as to adjust theapparent source of the emitted light from the emitters. In someexamples, additional imaging lenses can be used to detect scatteredlight reflected back from the target object.

The imaging range finder according to various examples of the disclosurecan provide several advantages over other range finders. For example,the range finder can emit light that has little or no spread as ittravels toward the target object. As a result, a maximum amount of lightcan contact the target object and be reflected back to the range finder,resulting in high optical efficiency. The range finder can also providenear- and far-distance range accuracy. The range finder can operate at awavelength longer than the range normally detected by traditionalphotodetectors, e.g., silicon photodetectors, so as to avoid visiblelight negative effects on detection, prevent or reduce adverse effectson human retinas, and “see” through less than ideal conditions of theobject and the environment. The range finder can also save power.

Various examples of the imaging range finder are described below.

Imaging Range Finder with Fixed Array and Lens

FIG. 1 illustrates an imaging range finder having a fixed array and lensaccording to various examples. In the example of FIG. 1, imaging rangefinder 100 can include combined emitter-photodetector array 110 foremitting and detecting light, and imaging lens 120 for collimating lightemitted by the array and focusing light received from an object backonto the array. The lens 120 can be a Fresnel lens or any other suitablelens, mirror, or optical component capable of performing the lensoperations. Because the lens 120 collimates the light, almost all thelight that the array 110 generates can be outputted, with little or nospread, by the range finder 100.

FIGS. 2A through 2C illustrate the array in more detail. In the exampleof FIG. 2A, the array 110 can include multiple nodes 211 on die 217 inan array configuration. Each node 211 can include a combined emitter foremitting light and photodetector for detecting light. FIGS. 2B and 2Cillustrate top and cross-sectional views, respectively, of the node 211.In each node 211, emitter 212 can be in the center of the node andsurrounded by photodetector 214. It should be understood that otherconfigurations of the emitter 212 and photodetector 214 are alsopossible, e.g., side-by-side, the photodetector surrounded by theemitter, and so on. In some examples, the numbers of emitters andphotodetectors can be the same. In some examples, the numbers ofemitters and photodetectors can be different. In the example of FIG. 2A,the emitters 212 and photodetectors 214 are disposed on the same die217. It should be understood however that more than one die can be used,where the emitters can occupy one die and the photodetectors anotherdie. Each die can have an adjacent lens, where the emitters' lens cancollimate light emitted by the emitters and the photodetectors' lens canfocus reflected light onto the photodetectors. In some examples, thedies can be located together. In some examples, the dies can be locatedat separate locations.

The emitter 212 can be a laser, such as a vertical-cavitysurface-emitting laser (VCSEL). The VCSEL can provide severaladvantages. It can emit light perpendicular to the array 110, providingfor more efficient operation. Its compact size can allow for densepacking of multiple VCSELs on the die. Its spectral and spatialcoherence allows for better collimation of the emitted light to betransmitted by the lens. The photodetector 214 can be a PIN photodiode.It should be understood that other suitable components capable ofperforming the functions of the emitter and the photodetector can alsobe used. For example, other emitters can include LEDs, optical fibers orfiber bundles, quantum dots, a micro mirror array, an LCD array, and anyother components capable of releasing or generating light as describedherein. Similarly, other photodetectors can include CCD sensors, LEDs,photoresisters, and any other components capable of detecting light asdescribed herein.

In some examples, the VCSELs can emit light at a wavelength of 1000 nmor higher; more preferably, 1300 nm or higher; and most preferably, 1550nm or higher. In some examples, the detection range of the photodetectorcan be matched to the emission spectrum of the VCSEL. A wavelength of1000 nm or higher can provide several advantages. Light transmission inthis wavelength range can be resistant to poor atmospheric conditions,e.g., humidity, haze, smog, fog, and so on. The atmospherictransmissivity in this wavelength range can have a value ofapproximately 1.0, indicating little or no absorption. Light in thiswavelength range can also emit at a maximum permissible exposure (MPE)level of approximately 1 J/cm² pulses for 1 ns or longer, which is wellwithin the levels considered safe for the eyes. The spectra of sunlightand most man-made light sources can contain less power in thiswavelength range. Spectral irradiance, indicative of detectable lightlevels, in this wavelength range can be approximately 0.75 W/m²/nm orlower, in contrast to full sunlight which has a spectral irradiance ofapproximately 2 W/m²/nm. Light in this wavelength range can also resultin less energy needed to generate photons for detection at thephotodetector. Hence, the power responsivity, indicative ofphotodetector light-to-current conversion, can be as high asapproximately 1.1 A/W and a quantum efficiency, indicative of thephotodetector's light sensitivity, can be approximately 84.1% or higherfor the photodetector.

Referring again to FIG. 1, in addition to the array 110 and lens 120,the imaging range finder 100 can include window 190 to hold the lens120. The window 190 can be a transparent, high refractive indexmaterial. The range finder 100 can also include anti-reflective (AR)coating 140 on the lens 120 and band-pass coating 150 on theundersurface of the window 190. The band-pass coating 150 can match thedesired wavelength range of the emitters 212, e.g., at 1000 nm orhigher. The range finder 100 can include application-specific integratedcircuit (ASIC) 130 to drive the array 110.

FIG. 3 illustrates an exemplary ASIC that can be used in the rangefinder 100. In the example of FIG. 3, ASIC 330 can include laser MUX 335to select which emitter 312 in the array 310 to emit light and laserdriver 336 to drive the MUX. The ASIC 330 can also include photodetectorMUX 331 to select which photodetector 314 in the array 310 to detectlight and analog front-end 332 to drive the MUX. The ASIC 330 caninclude interface and control circuits 333 to control the emitter andphotodetector components such that the emitter-photodetector pairs worktogether during operation. The interface and control circuits 333 canalso connect via an interface to external components in communicationwith the range finder 100. The ASIC 330 can also include voltageregulators 334, e.g., low dropout (LDO) regulators, to regulate thepower supply to the ASIC.

In operation, the ASIC 330 can drive one or more of the emitters 312 andtheir corresponding photodetectors 314 to emit light from the selectedemitters and to detect light received at the selected photodetectors.

It should be understood that the ASIC components are not limited tothose described here, but can include other and/or additional componentscapable of driving the array according to various examples.

Referring again to FIG. 1, the imaging range finder 100 can include vias160, e.g., a through-silicon via (TSV), through which electricalconnections can be made from the power supply, processors, memory,analog circuits, and the like to electrical components in the rangefinder, e.g., to the ASIC 130. The range finder 100 can also includebonding material 180 to bond the array portion to the lens portion ofthe range finder. The bonding material 180 can be any suitabletransparent, adhesive material, e.g., epoxy resin. The range finder 100can also include solder balls 170 on the lower surface to connect therange finder to a circuit board.

The range finder 100 can operate as follows. The ASIC 130 can drive oneor more of the emitters 212 in the array 110 to emit light. Multipleemission patterns can be used according to the design of the system inwhich the range finder 100 is to be used. For example, a single emitter212 can be driven to emit light. Or each emitter 212 can be driven oneat a time either sequentially or randomly. Or all the emitters 212 canbe driven simultaneously. Or a subset of emitters 212 can be driventogether, followed by another subset, and so on. The ASIC 130 canconcurrently drive the photodetector(s) 214 corresponding to the drivenemitter(s) 212.

The lens 120 can receive and collimate the emitted light from theemitters 212. The lens 120 can then output the collimated light toward atarget object. The target object can reflect the light back to the lens120. The lens 120 can capture the reflected light and focus it on thephotodetectors 214. The photodetectors 214 driven by the ASIC 130 candetect the focused light from the lens 120 and transmit a detectionsignal to the ASIC 130 or other components for processing.

FIGS. 4A through 4D depict exemplary light paths for the range finder100. In the example of FIG. 4A, the light path from the array 410 toobject 480 is depicted when light is emitted from an emitter 411 at afirst position in the array. Here, the emitter in the combinedemitter-photodetector 411 can emit light 415. The imaging lens 420 cancollimate the emitted light 415 and output the collimated light 416toward the target object 480. The focal length F of the lens 420 isshown. The collimated light 416 can contact the object 480 at locationA. In the example of FIG. 4B, light is emitted from an emitter 411 at asecond position in the array 410. Here, the collimated light 416 cancontact the object 480 at a different location A′. In the example ofFIG. 4C, light is emitted from an emitter 411 at a third position in thearray 410, which coincides with the center of the lens 420. Here, thecollimated light 416 can contact the object 480 at another location A″.FIGS. 4A through 4C demonstrate how the light path can vary depending onwhich emitter is used, thereby providing flexibility in directing lighttoward the object to get the optimal detection.

In the example of FIG. 4D, the reflected light path from the object 480back to the array 410 is depicted. Here, the object 480 can reflect thelight 417 back to the lens 420 along the reverse path that the lighttraveled to the object, e.g., in FIG. 4A. It should be noted that,because the object 480 typically has non-smooth surfaces, some of thereflected light can scatter away from the reverse path, though themajority of the light can tend to follow the reverse path. However, forexplanatory purposes, only the light reflected along the reverse path isdepicted. The lens 420 can focus the light 418 and transmit it to thephotodetector in the combined emitter-photodetector 411 for detection.

FIGS. 4A through 4D depict examples in which the object reflects backthe light from the range finder. It should be understood, however, thatsome objects can also generate their own light and transmit that lightto the range finder for detection, along light paths similar to thoseshown in FIG. 4D. For example, another range finder or any othersuitable light emitting device can generate and emit light, e.g., fromlocation A (in FIG. 4A) toward the lens. The lens can then focus thegenerated light and transmit it to the photodetector in the array fordetection.

The imaging range finder of FIG. 1 can operate in various modes. FIGS.5A through 5F illustrate exemplary modes of operation. In the example ofFIG. 5A, the range finder can operate in time-of-flight (TOF) mode, inwhich the range finder can use the time lapse or time difference betweenthe emitters emitting light and the photodetectors detecting thereflected light to find the proximate range or distance of the targetobject. In TOF mode, one or more emitters in the array can emit light(530). The lens can collimate the emitted light (531). The lens canoutput the collimated light toward the target object (532). The lens canthen receive back portions of the collimated light reflected from theobject (533). The lens can focus the reflected light onto one or morephotodetectors in the array (534). The photodetectors can detect thefocused light (535). A processor can then calculate the proximate rangeof the object based on the time difference between the time that theemitters emitted light and the time that the photodetectors detectedreflected light (536). The processor can be either the range finder ASICor a system processor in communication with the range finder.

The time difference t_(d) can be calculated as t_(d)=(t₂−t₀)/2=t, wheretime t₀=0, the time at which the range finder emits a light pulse; timet₁=t, the time at which the pulse contacts a target object; and timet₂=2t, twice t₁ and the time at which the range finder detects a lightpulse reflected from the object. Because of timing issues betweenemitter actuation and light travel, the time difference t_(d) caninclude excess time, which can result in inaccurate range calculations.

The following exemplary method can be used to improve the accuracy ofthe time difference t_(d) calculation. A predefined time period can bedivided into equal segments beginning at t₀=0. For example, a timeperiod of 100 ns can be divided into 1 ns increments at 1 ns, 2 ns, 3ns, and so on. The predefined time period can be longer than the timerequired for the light to reflect back from the object to the rangefinder. An emitter can emit a light pulse at t₀=0. A photodetector canbe monitored beginning at t₀=0 and the detection signal of thatphotodetector recorded at each 1 ns increment. At around time t₂=2t, thecorresponding 1 ns increments can show an increase in the detectionsignal to indicate the reflected light pulse from the object. Because ofthe timing issues mentioned previously, the detection signal canstraddle multiple 1 ns increments, such that it is difficult toprecisely determine time t₂.

Hence, this method can be repeated with a shift in the time segments soas to better determine time t₂. For example, the time segments can beshifted by δ to begin at t₀′=0+δ. As such, the increments can be at 1 nsincrements of (0+δ) ns, (1+δ) ns, (2+δ) ns, and so on. The emitter canemit another light pulse at t₀=0 and the photodetector can be monitoredbeginning at t₀=0, but with the detection signal recorded at each +δ nsincrement. At around time t₂=2t, the corresponding +δ ns increment(s)can show an increase in the detection signal with a differentdistribution of the signal than previously. If time t₂ still cannot bedetermined with reasonable precision, the time segments can be shiftedagain by some other amount and the method repeated. In some examples,the method can be repeated approximately 10 times to determine areasonable time t₂, resulting in a highly accurate proximate rangecalculation.

Another exemplary method to improve the accuracy of the time differencet_(d) calculation can be as follows. An emitter can emit a light pulsetoward a target object and a photodetector can detect a light pulsereflected back from the object. The processor can calculate a timedifference t_(d) for an initial coarse measurement. The emitter can thenemit a pulse train toward the object. In some examples, the pulse traincan be 10 or more pulses. The photodetector can detect a pulse trainreflected back from the object. To determine the error in time t₂, theprocessor can pair each emitted pulse with its reflected pulse andcalculate the time difference t_(d) between each pair. For each pair,the processor can then subtract the coarse t_(d) measurement from eachpair's t_(d) measurement. The subtraction results can be averaged andthe average deemed the error in time t₂. Subsequent t_(d) measurementscan be adjusted using this average to eliminate or reduce this error.

It should be understood that the time difference calculations are notlimited to those described herein, but can include other methods capableof improving the accuracy of the calculation.

In the example of FIG. 5B, the range finder can operate inproportional-to-intensity mode, in which the range finder can use theintensity of the reflected light to find the proximate range of thetarget object. This mode is similar to the TOF mode of FIG. 5A with theexception of the last action (546) of FIG. 5B. Here, after thephotodetectors detect the focused light (545), the processor cancalculate the proximate range of the object based on the intensity ofthe focused light detected at the photodetectors (546). The higher thelight intensity, the closer the object. When the object is closer, thelens can collect more of the reflected light from the object, therebyfocusing higher intensity light on the photodetectors.

In the example of FIG. 5C, the range finder can operate in a passivemode of the proportional-to-intensity mode, in which the range findercan capture an image based on the focused light, rather than activelyprocessing the light intensity. This mode is also similar to the TOFmode of FIG. 5A with the exception of the last actions (556-557) of FIG.5C. Here, after the photodetectors detect the focused light (555), theprocessor can capture the detection signals from the photodetectors andform an image therefrom (556). The processor can then process the imageto find a proximate range of the object based on characteristics of theimage, e.g., the object size in the image (557). In passive mode, therange finder can also detect ambient light present in the scene with noillumination from the emitters.

In the example of FIG. 5D, the range finder can operate in Doppler shiftmode, in which the range finder can capture sound emanating from thetarget object. In the Doppler shift mode, the range finder can operateas a sound recorder or player. The processor can generate a sine wavetone (560) and modulate one or more emitters with the tone (561). Theemitters can emit light modulated at the tone (562). The lens cancollimate the emitted light (563) and output the collimated light towardthe target object (564). If the object is emitting a sound wave, thesound wave can modulate the light reflected back from the object to thelens. Accordingly, the lens can receive light modulated with theobject's sound wave (565). The lens can focus the modulated light on oneor more photodetectors in the array (566). The photodetectors can detectthe focused light (567). Upon receipt of the detection signal from thephotodetectors, the processor can demodulate the focused light tocapture the sound wave for recording or playback (568).

In the example of FIG. 5E, the range finder can operate in free-spaceoptical mode, in which the range finder can transmit and receive opticalcommunications with the target object. In this mode, the range findercan operate as a communication device. The processor can encode a firstset of data (570). One or more emitters can emit light (571). Theprocessor can embed the encoded data in the emitted light (572). Thelens can collimate the light with the encoded data (573) and output thecollimated light toward a target object, where the object can receiveand decode the data (574). In some examples, the target object can be asecond range finder or other suitable device capable of receiving andtransmitting an optical communication. If the object also has data totransmit to the range finder, the object can similarly encode a secondset of data, emit light, and embed the encoded data on the lighttransmitted from the object to the lens. If the object does not havedata to transmit, the object can simply send an encoded ACK signal withthe emitted light, indicating receipt of the first set of data from therange finder. Accordingly, the lens can receive light with the object'sencoded data from the object (575). The lens can focus the light on oneor more photodetectors in the array (576). The photodetectors can detectthe focused light (577). Upon receipt of the detection signal from thephotodetectors, the processor can decode the second set of data in thefocused light and store the decoded data for further processing (578).

In the example of FIG. 5F, the range finder can also operate in thefree-space optical mode, in which the range finder can bounce light offa surface of a predefined space, e.g., within a room, to detect thepresence of one or more other objects in the same space. In this mode,the range finder can operate as an object detector. One or more emittersin the array can emit light (580). In some examples, the light can beemitted in a pattern unique to the range finder for identifying therange finder. The lens can collimate the emitted light (581) and outputthe collimated light toward a surface in the space, e.g., toward theceiling, the wall, or the floor in the space (582). If a target objectis in the same space, the object can detect the emitted light and emitlight in response. In some examples, the target object can be a secondrange finder or other suitable device capable of receiving andtransmitting an optical communication. In some examples, the object canemit its unique pattern for identification. Accordingly, the rangefinder's lens can receive the object's emitted light (583) and focus thelight on one or more photodetectors in the array (584). Thephotodetectors can detect the focused light (585). Upon receipt of thedetection signal from the photodetectors, the processor can confirm thepresence of the object in the space and, optionally, identify the objectfrom its light pattern (586).

It should be understood that the operating modes are not limited tothose described herein, but can include other modes in which the rangefinder can operate according to various examples.

FIGS. 6A through 6D illustrate an exemplary fabrication process for theimaging range finder 100 of FIG. 1. In the example of FIG. 6A, thefabrication process can start by cutting a transparent wafer to formwindow 690 and sputter coating the undersurface of the window withband-pass coating 650. In some examples, the coating 650 can match thewavelength range of the emitters and photodetectors to act as a lightfilter. In the example of FIG. 6B, a gel material can be deposited ontothe window 690, molded to form imaging lens 620, and cured with UVlight. As an alternative to this gel molding, the lens 620 can be formedby molding a thermoplastic resin at elevated temperatures; molding athermoset resin and curing at elevated temperatures; etching a profileinto the transparent wafer; placing an equivalent volume of material andreflowing it to form a droplet shape in the form of a section of asphere; diamond turning or other methods of precision machining of anysuitable optical material; bonding a lens formed in a separate processto the top of the window; or the like. AR coating 640 can be depositedonto the formed lens 620 to coat the lens.

In the example of FIG. 6C, ASIC 630 can be provided and vias 660 formedin the ASIC. Solder balls 670 can be attached to the undersurface of theASIC 630. Combined emitter-photodetector array 610 can be provided andbonded to the ASIC 630. In the example of FIG. 6D, the fabricated lensportion of FIG. 6B and the fabricated array portion of FIG. 6C can bebonded together, with the array 610 and lens 620 aligned, using bondingmaterial 680 to form the imaging range finder 100 of FIG. 1.

It should be understood that the fabrication process is only an example,as other processes can also be used according to the available equipmentand material.

Imaging Range Finder with Movable Prism

FIG. 7 illustrates an imaging range finder having a movable prismaccording to various examples. The movable prism can rotate and tilt,thereby adjusting the emitted light path to different angles so that itappears as if the emitter has shifted to a new location. In someexamples, the maximum shift can be ±(emitter pitch/2). This canadvantageously allow the range finder to direct light at the targetobject so as to get the optimal detection of that object. In the exampleof FIG. 7, imaging range finder 700 can include combinedemitter-photodetector array 710 and imaging lens 720, similar to thearray 110 and lens 120 of FIG. 1. The range finder 700 can also includewindow 790, AR coating 740, band-pass coating 720, vias 760, 761, andsolder balls 770, similar to the window 190, AR coating 140, band-passcoating 120, vias 160, and solder balls 170 of FIG. 1.

The range finder 700 can include tilt prism 735 disposed in a cavitybetween the array 710 and the lens 720 to adjust the transmitted andreceived light. The prism 735 can rotate and tilt within the cavity.Inert gas 745 or some other suitable fluid, e.g., gel, liquid, emulsion,solution, gas, and so on, can fill the cavity. AR coating 740 can coatthe upper and lower surfaces of the prism 735. The range finder 700 canalso include microelectromechanical (MEMS) device 715 connected to theprism 735 to rotate and tilt the prism. ASIC 730 in the range finder 700can drive the array 710 and the MEMS device 715.

FIG. 9 illustrates an exemplary ASIC that can be used in the rangefinder 700. In the example of FIG. 9, ASIC 930 can include laser MUX935, photodetector MUX 931, analog front-end 932, interface and controlcircuits 933, and voltage regulators 934, which can operate in the sameor similar manner as the laser MUX 335, photodetector MUX 331, analogfront-end 332, interface and control circuits 333, and voltageregulators 334 of FIG. 3.

The ASIC 930 can also include MEMS MUX 937 to select MEMS drive lines916 and MEMS sense lines 917 in MEMS device 915. The drive lines 916 canbe used to transmit control commands to the MEMS device 915 to controlthe rotation and tilt of the prism. The sense lines 917 can be used totransmit rotation and tilt measurements to MEMS analog front-end 938.The MEMS analog front-end 938 can drive the MUX 937 and connect to thepower supply.

In operation, the ASIC 930 can drive one or more of the emitters 912 andtheir corresponding photodetectors 914 to emit and detect light. TheASIC 930 can concurrently drive the MEMS device 915 to move the prism735.

Referring again to FIG. 7, the range finder 700 can operate as follows.The ASIC 730 can drive one or more of the emitters in the array 710 toemit light. As described previously in FIG. 1, multiple emissionpatterns can be used according to the system in which the range finder700 is to be used. The ASIC 730 can also drive the prism 735 to transmitthe emitted light from the array 710 to the lens 720. The ASIC 730 candrive the prism 735 to either a position parallel to the array 710 andthe lens 720, a tilted position, or a rotated position. Depending on itsposition, the prism 735 can adjust the angle of the emitted light fromthe array 710 as the light passes through the prism. The lens 720 canreceive and collimate the emitted light from the prism 735. The lens 720can then output the collimated light toward a target object. The targetobject can reflect the light back to the lens 720. The lens 720 cancapture and focus the reflected light. The prism 735 can transmit thefocused light to the photodetectors in the array 710. Depending on itsposition, the prism 735 can adjust the angle of the focused light as thelight passes through the prism. The photodetectors driven by the ASIC730 can detect the focused light and transmit a detection signal to theASIC 730 or other components for processing.

FIGS. 8A through 8E depict exemplary light paths for the range finder700 based on the position of the prism. In the example of FIG. 8A, thelight path from the array 810 to object 880 with a parallel prism 835 isdepicted. Here, the emitter in the combined emitter-photodetector 811can emit light 815. The parallel prism 835 can adjust the angle of theemitted light and transmit the light 819 to the lens 820. Forsimplicity, in this example, the portion of the parallel prism 835through which the emitted light passes does not adjust the light angle.The lens 820 can collimate the light 819 and output the collimated light816 toward the target object 880. The collimated light 816 can contactthe object 880 at location A.

In the example of FIG. 8B, the light path from the array 810 to theobject 880 is depicted in which the prism 835 has rotated. Here, theemitter can emit light 815. The portion of the rotated prism 835 throughwhich the emitted light passes can refract the light, thereby changingthe light angle. The prism 835 can transmit the adjusted emitted light819 to the lens 820. The lens 820 can collimate the light 819 and outputthe collimated light 816 toward the target object 880. Because the prism835 adjusted the light angle, the collimated light 816 can contact theobject 880 at new location B, rather than location A in FIG. 8A.

In the example of FIG. 8C, the reflected light path from the object 880back to the array 810 is depicted in which the prism 835 has rotated.Here, the object 880 can reflect the light 817 back to the lens 820along the reverse path that the light traveled to the object, e.g., inFIG. 8B. The lens 820 can focus the light 818 and transmit it to therotated prism 835. The prism 835 can refract the light, thereby changingthe light angle, and transmit the adjusted focused light 814 to thephotodetector in the combined emitter-photodetector 811 for detection.Because the prism 835 adjusted the light angle, the focused light 814can contact the photodetector at position B′ in the array, rather thanthe photodetector at position A′, which corresponds to the emitter thatemitted the light in FIG. 8B.

Although the light 815 was emitted from the emitter at position A′ inFIG. 8B, the light appears to have been emitted from the emitter atposition B′ in FIG. 8C. The net effect is that, because of the rotatedprism 835, the emitted light can be adjusted to contact the object 880at position B, rather than position A in FIG. 8A. As stated previously,this can advantageously allow the range finder flexibility in directinglight toward the object to get the optimal detection.

Similar results can be realized with a tilted prism. In the example ofFIG. 8D, the light path from the array 810 to the object 880 is depictedin which the prism 835 has tilted. Here, the tilted prism 835 canrefract the emitted light 815, thereby changing the light angle. Becausethe prism 835 adjusted the light angle, the collimated light 816 fromthe lens 820 can contact the object 880 at new location C, rather thanlocation A in FIG. 8A or location B in FIG. 8B.

In the example of FIG. 8E, the reflected light path from the object 880back to the array 810 is depicted in which the prism 835 has tilted.Here, the tilted prism 835 can refract the focused light 818 from thelens 820, thereby changing the light angle. Because the prism 835adjusted the light angle, the adjusted focused light 814 can contact thephotodetector at position C′ in the array, rather than the photodetectorat position A′, which corresponds to the emitter that emitted the lightin FIG. 8D.

The net effect is that, because of the tilted prism 835, the emittedlight can be adjusted to contact the object 880 at position C.

FIGS. 10A through 10E illustrate an exemplary fabrication process forthe imaging range finder 700 of FIG. 7. In the example of FIG. 10A, thefabrication process can start by cutting a transparent wafer to formwindow 1090. In the example of FIG. 10B, the window 1090 can be thinnedand a hollow etched into its undersurface. The hollow can be sputtercoated with band-pass coating 1050. Imaging lens 1020 can be formed onthe window 1090 using any of the methods previously described in FIG.6B. AR coating 1040 can be deposited onto the formed lens 1020 to coatthe lens.

In the example of FIG. 10C, a transparent material can form prism 1035.The upper and lower surfaces of the prism 1035 can be sputter coatedwith band-pass coating 1050. In the example of FIG. 10D, ASIC 1030 canbe provided and vias 1060 formed in the ASIC. Solder balls 1070 can besputtered onto the undersurface of the ASIC 1030. Combinedemitter-photodetector array 1010 can be provided and bonded to the ASIC1030.

In the example of FIG. 10E, the fabricated lens portion of FIG. 10B andthe fabricated array portion of FIG. 10D can be brought together to forma cavity. The prism 1035 can be positioned within the cavity. MEMSdevice 1015 can be provided and vias 1061 formed in the MEMS device. TheMEMS device 1015 can be connected to the prism 1035. Inert gas or someother suitable material can fill the cavity. The cavity can be sealedwith hermetic seal 1055 to bond the fabricated lens and array portionstogether, with the array 1010, prism 1035, and lens 1020 aligned, toform the imaging range finder 700 of FIG. 7.

The imaging range finder 700 of FIG. 7 can operate in any of theoperating modes of FIGS. 5A through 5F.

Imaging Range Finder with Movable Array

FIG. 11 illustrates an imaging range finder having a movable combinedemitter-photodetector array according to various examples. The array canmove along its x- and y-axes, thereby adjusting the emitted light pathto different angles according to the shifted emitter position. In someexamples, the maximum shift can be ±(emitter pitch/2). This canadvantageously allow the range finder to direct light at the targetobject so as to get the optimal detection of that object. In the exampleof FIG. 11, imaging range finder 1100 can include combinedemitter-photodetector array 1110 and imaging lens 1120, similar to thearray 110 and lens 120 of FIG. 1. The range finder 1100 can also includewindow 1190, AR coating 1140, band-pass coating 1120, vias 1160, andsolder balls 1170, similar to the window 190, coatings 140 and 120, vias160, and solder balls 170 of FIG. 1.

The range finder 1100 can also include MEMS device 1115 to connect tothe array 1110 and ASIC 1130 using bonding material 1180 to move thearray within a cavity. The cavity can be formed by substrate 1195supporting the MEMS device 1115, array 1110, and ASIC 1130 and thewindow 1190 supporting the lens 1120. Inert gas 1145 or some othersuitable material can fill the cavity. ASIC 1130 in the range finder1100 can drive the array 1110 and the MEMS device 1115.

FIG. 13 illustrates an exemplary ASIC that can be used in the rangefinder 1100. In the example of FIG. 13, ASIC 1330 can be the same as theASIC 930 in FIG. 9, except that MEMS MUX 1337 in FIG. 13 can connect tothe MEMS device 1315 disposed below, instead of above, the ASIC 1330.The MEMS MUX 1337 can select MEMS drive lines 1316 and MEMS sense lines1317 in the MEMS device 1315. The drive lines 1316 can be used totransmit control commands to the MEMS device 1315 to control themovement of the array 1310. The sense lines 1317 can be used to transmitposition measurements to MEMS analog front-end 1338.

In operation, the ASIC 1330 can drive one or more of the emitters 1312and their corresponding photodetectors 1314 to emit and detect light.The ASIC 1330 can concurrently drive the MEMS device 1315 to move thearray 1310.

Referring again to FIG. 11, the range finder 1100 can operate asfollows. The ASIC 1130 can drive one or more of the emitters in thearray 1110 to emit light. As described previously in FIG. 1, multipleemission patterns can be used according to the system in which the rangefinder 1100 is to be used. The ASIC 1130 can also drive the array 1110to move along its x- or y-axes. The lens 1120 can receive and collimatethe emitted light from the array 1110. The amount that the lens 1120refracts the emitted light as it passes through the lens can depend onthe position of the emitters in the array 1110. Accordingly, if thearray 1110 moves, the lens 1120 can output the collimated light toward atarget object at a different angle. The target object can reflect thelight back to the lens 1120. The lens 1120 can capture and focus thereflected light. The lens 1120 can transmit the focused light to one ormore photodetectors in the array 1110. The photodetectors driven by theASIC 1130 can detect the focused light and transmit a detection signalto the ASIC 1130 or other components for processing.

FIGS. 12A and 12B depict exemplary light paths for the range finder 1100based on the position of the array. In the example of FIG. 12A, thelight path from the array 1210 to object 1280 is depicted. Here, theemitter in the combined emitter-photodetector 1211 can emit light 1215.The lens 1220 can collimate the light 1215 and output the collimatedlight 1216 toward the target object 1280. The collimated light 1216 cancontact the object 1280 at location A.

In the example of FIG. 12B, the light path from the array 1210 to theobject 1280 is depicted in which the array 1210 has moved. Here, theemitter can emit light 1215 from a different position relative to thelens 1220. The portion of the lens 1220 through which the emitted light1215 passes can refract the light at a different angle that in FIG. 12A,thereby changing the light angle. The lens 1220 can collimate the light1215 and output the adjusted collimated light 1213 toward the targetobject 1280. Because the lens 1220 adjusted the light angle, thecollimated light 1213 can contact the object 1280 at new location B,rather than location A in FIG. 12A.

The net effect is that, because of the movable array 1210, the emittedlight can be adjusted to contact the object 1280 at position B, ratherthan position A in FIG. 12A. As stated previously, this canadvantageously allow the range finder flexibility in directing lighttoward the object to get the optimal detection.

FIGS. 12A and 12B depict the array moving along its x-axis. Similarresults can be realized with the array moving along its y-axis to movethe light contact position at the target object.

FIGS. 14A through 14E illustrate an exemplary fabrication process forthe imaging range finder 1100 of FIG. 11. In the example of FIG. 14A,the fabrication process can start by cutting a transparent wafer to formwindow 1490 and bonding wafer 1492. The window 1490 and wafer 1492 canbe bonded together. In the example of FIG. 14B, portions of the wafer1492 can be etched away to expose the undersurface of the window 1490.The exposed undersurface can be sputter coated with band-pass coating1450. Imaging lens 1420 can be formed on the window 1490 using any ofthe methods previously described in FIG. 6B AR coating 1440 can bedeposited onto the formed lens 1420 to coat the lens.

In the example of FIG. 14C, MEMS device 1415 can be provided and bondedto substrate 1495. Solder balls 1470 can be sputtered onto theundersurface of the substrate 1495. Vias 1460 can be formed in thesubstrate 1495. Bonding material 1480 can be deposited onto the MEMSdevice 1415 in preparation for bonding combined emitter-photodetectorarray 1410 and ASIC 1430 thereto. In the example of FIG. 14D, the array1410 and ASIC 1430 can be provided and bonded together. Vias 1461 can beformed in the ASIC 1430. The bonded array 1410 and ASIC 1430 can bebonded to the MEMS portion by the bonding material 1480.

In the example of FIG. 14E, the fabricated lens portion of FIG. 14B andthe fabricated array portion of FIG. 14D can be brought together to forma cavity. Inert gas or some other suitable material can fill the cavity.The cavity can be sealed with hermetic seal 1455 to bond the fabricatedlens and array portions together, with the array 1410 and lens 1420aligned, to form the imaging range finder 1100 of FIG. 11.

The imaging range finder 1100 of FIG. 11 can operate in any of theoperating modes of FIGS. 5A through 5F.

Imaging Range Finder with Movable Lens

FIG. 15 illustrates an imaging range finder having a movable imaginglens according to various examples. The lens can move along its x- andy-axes, thereby adjusting the collimated light path to different anglesaccording to the shifted lens position. This can advantageously allowthe range finder to direct light at the target object so as to get theoptimal detection of that object. In the example of FIG. 15, imagingrange finder 1500 can include combined emitter-photodetector array 1510,similar to the array 110 of FIG. 1. The range finder 1500 can alsoinclude window 1590, AR coating 1540, band-pass coating 1520, vias 1560,1561, and solder balls 1570, similar to the window 190, coatings 140 and120, vias 160, and solder balls 170 of FIG. 1.

The range finder 1500 can include imaging lens 1520, similar to the lens120 of FIG. 1. Here, the lens 1520 can be either a single- ordouble-sided Fresnel lens or any other lens suitable for the rangefinder.

The range finder 1500 can further include MEMS device 1515 to connect tothe lens 1520 to move the lens within a cavity. The cavity can be formedby the window 1590 and exit window 1585. ASIC 1530 can support the array1510 within a second cavity formed by the ASIC and the window 1590.Inert gas 1545 or some other suitable material can fill the lens cavityand/or the array cavity. ASIC 1530 can drive the array 1510 and the MEMSdevice 1515.

The ASIC 1530 can have the same or similar configuration as the ASIC 930in FIG. 9. The ASIC 1530 can operate in a similar manner as well, exceptthe ASIC 1530 can drive the MEMS device 1515 to move the lens 1520,rather than the prism 735 of FIG. 7.

The range finder 1500 can operate as follows. The ASIC 1530 can driveone or more of the emitters in the array 1510 to emit light. Asdescribed previously in FIG. 1, multiple emission patterns can be usedaccording to the system in which the range finder 1500 is to be used.The ASIC 1530 can also drive the lens 1520 to move along its x- ory-axes. The lens 1520 can receive and collimate the emitted light fromthe array 1510. The amount that the lens 1520 refracts the emitted lightas it passes through the lens can depend on the position of the lens.Accordingly, if the lens 1520 moves, it can output the collimated lighttoward a target object at a different angle. The target object canreflect the light back to the lens 1520. The lens 1520 can capture andfocus the reflected light and can transmit the focused light to one ormore photodetectors in the array 1510. The photodetectors driven by theASIC 1530 can detect the focused light and transmit a detection signalto the ASIC 1530 or other components for processing.

FIGS. 16A and 16B depict exemplary light paths for the range finder 1500based on the position of the lens. In the example of FIG. 16A, the lightpath from the array 1610 to object 1680 is depicted. Here, the emitterin the combined emitter-photodetector 1611 can emit light 1615. The lens1620 can collimate the light 1615 and output the collimated light 1616toward the target object 1680. The collimated light 1616 can contact theobject 1680 at location A.

In the example of FIG. 16B, the light path from the array 1610 to theobject 1680 is depicted in which the lens 1620 has moved. Here, theemitter can emit light 1615 and contact the lens 1620 at a differentposition because the lens has moved. The portion of the lens 1620through which the emitted light 1615 passes can refract the light at adifferent angle that in FIG. 16A, thereby changing the light angle. Thelens 1620 can collimate the light 1615 and output the adjustedcollimated light 1613 toward the target object 1680. Because the lens1620 adjusted the light angle, the collimated light 1613 can contact theobject 1680 at new location B, rather than location A in FIG. 16A.

The net effect is that, because of the movable lens 1620, the emittedlight can be adjusted to contact the object 1680 at position B in FIG.16B, rather than position A in FIG. 16A. As stated previously, this canadvantageously allow the range finder flexibility in directing lighttoward the object to get the optimal detection.

FIGS. 16A and 16B depict the lens moving along its x-axis. Similarresults can be realized with the lens moving along its y-axis to movethe light contact position at the target object.

FIGS. 17A through 17F illustrate an exemplary fabrication process forthe imaging range finder 1500 of FIG. 15. In the example of FIG. 17A,the fabrication process can start by cutting a transparent wafer to formexit window 1785 and bonding wafer 1792. The exit window 1785 and wafer1792 can be bonded together. In the example of FIG. 17B, portions of thewafer 1792 can be etched away to expose the undersurface of the exitwindow 1785, forming a hollow for housing imaging lens 1720.

In the example of FIG. 17C, imaging lens 1720 can be formed using any ofthe methods previously described in FIG. 6B. AR coating 1740 can bedeposited onto the formed lens 1720 to coat the lens. In the example ofFIG. 17D, a transparent wafer can be cut to form window 1790. MEMSdevice 1715 can be provided and bonded to the window 1790. Theundersurface of the window 1790 can be sputter coated with band-passcoating 1750. Bonding material 1795 can be deposited on the undersurfacein preparation for bonding with ASIC 1730.

In the example of FIG. 17E, ASIC 1730 can be provided and vias 1760formed in the ASIC. Solder balls 1770 can be sputtered onto theundersurface of the ASIC 1730. Combined emitter-photodetector array 1710can be provided and bonded to the ASIC 1730.

In the example of FIG. 17F, the fabricated exit window portion of FIG.17B and the fabricated MEMS portion of FIG. 17D can be put together toform a cavity. The lens 1720 can be positioned on the MEMS device 1715within the cavity. The cavity can be sealed with hermetic seal 1755.This structure can be put together with the fabricated array portion ofFIG. 17E to form a second cavity therebetween. The second cavity canalso be sealed with the hermetic seal 1755. Inert gas or some othersuitable material can fill either or both the cavities. The via 1761 inthe ASIC 1730 can be extended through the window 1790 and bondingmaterial 1795 to allow electric connection to the MEMS device 1715. Theresulting structure, with the array 1710 and lens 1720 aligned, can formthe imaging range finder 1500 of FIG. 15.

The imaging range finder 1500 of FIG. 15 can operate in any of theoperating modes of FIGS. 5A through 5F.

Imaging Range Finder with Movable Array and Lens

FIG. 18 illustrates an imaging range finder having both a movableimaging lens and a movable array according to various examples. The lensand the array can move along their respective x- and y-axes, therebyadjusting the light path to different angles according to the shiftedlens and array positions. This can advantageously allow the range finderto direct light at the target object so as to get the optimal detectionof that object.

In the example of FIG. 18, imaging range finder 1800 can includecombined emitter-photodetector array 1810 and imaging lens 1820. Thearray 1810 can be the same or similar to the array 110 of FIG. 1. Therange finder 1800 can also include first MEMS device 1815 to connect tothe array 1810 and ASIC 1830 using bonding material 1880 to move thearray within a cavity. The cavity can be formed by substrate 1895supporting the first MEMS device 1815, array 1810, and ASIC 1830 and bywindow 1890 supporting the lens 1820 and second MEMS device 1816.

The lens 1820 can be the same or similar to the lens 1510 of FIG. 15.The second MEMS device 1816 can connect to the lens 1820 to move thelens within a second cavity. The second cavity can be formed by thewindow 1890 and exit window 1885. Inert gas or some other suitablematerial can fill the lens cavity and/or the array cavity.

The range finder 1800 can also include AR coating 1840 to coat the lens1820, band-pass coating 1850 to coat an undersurface of the window 1890,solder balls 1870 on an undersurface of the substrate 1895, and hermeticseals 1855, 1856 to seal the cavities. The range finder 1800 can formvias 1861 through the substrate 1895, window 1890, and exit window 1885to allow electrical connections to the ASIC 1830 and two MEMS devices1815, 1816.

The ASIC 1830 can drive the array 1810 and the two MEMS devices 1815,1816. The ASIC 1830 can have the same or similar configuration as theASIC 930 in FIG. 9. The ASIC 1830 can operate in a similar manner aswell, except the ASIC 1830 can drive the two MEMS device 1815, 1816 tomove the lens 1820 and the array 1810, rather than the prism 735 of FIG.7.

The range finder 1800 can operate as follows. The ASIC 1830 can driveone or more of the emitters in the array 1810 to emit light. Asdescribed previously in FIG. 1, multiple emission patterns can be usedaccording to the system in which the range finder 1500 is to be used.The ASIC 1830 can also drive the array 1810 and the lens 1820 to movealong their respective x- or y-axes. The lens 1820 can receive andcollimate the emitted light from the array 1810. The amount that thelens 1820 refracts the emitted light as it passes through the lens candepend on the position of the lens and the array 1810. Accordingly, ifthe lens 1820, the array 1810, or both move, the lens 1820 can outputthe collimated light toward a target object at a different angle. Thetarget object can reflect the light back to the lens 1820. The lens 1820can capture and focus the reflected light and can transmit the focusedlight to one or more photodetectors in the array 1810. Thephotodetectors driven by the ASIC 1830 can detect the focused light andtransmit a detection signal to the ASIC 1830 or other components forprocessing.

The light paths in the range finder 1800 can be adjusted because of lensand/or array movement in the same or similar manner as depicted in FIGS.12A and 12B (array movement) and FIGS. 16A and 16B (lens movement). Thenet effect is that, because of the movable lens 1820 and/or movablearray 1810, the emitted light can be adjusted to contact a target objectat adjusted positions. This can advantageously allow the range finderflexibility in directing light toward the object to get the optimaldetection.

An exemplary fabrication process for the imaging range finder 1800 canbe a hybrid of the fabrication in FIGS. 14A through 14E of a movablearray and the fabrication in FIGS. 17A through 17F of a movable lens.For example, the fabrication process for the range finder 1800 of FIG.18 can start by cutting a transparent wafer to form exit window 1885 anda bonding wafer to attach to the exit window. Portions of the bondingwafer can then be etched away to expose the undersurface of the exitwindow 1885, forming a hollow for housing lens 1820.

Imaging lens 1820 can be formed using any of the methods previouslydescribed in FIG. 6B. AR coating 1840 can be deposited onto the formedlens 1820 to coat the lens. A transparent wafer can be cut to formwindow 1890. Second MEMS device 1816 can be provided and bonded to thewindow 1890. The undersurface of the window 1890 can be sputter coatedwith band-pass coating 1850. Bonding material can be deposited on theundersurface of the window 1890, forming a hollow for housing array 1810and ASIC 1830.

The first MEMS device 1815 can be provided and bonded to the substrate1895. The solder balls 1870 can be sputtered onto the undersurface ofthe substrate 1895. The vias 1860 can be formed in the substrate 1895.The bonding material 1880 can be deposited onto the first MEMS device1815. The array 1810 and the ASIC 1830 can be provided and bondedtogether. Vias 1862 can be formed in the ASIC 1830. The bonded array1810 and ASIC 1830 can be bonded to the first MEMS device 1815 by thebonding material 1880.

The fabricated exit window portion and the fabricated second MEMS deviceportion can be put together to form a cavity. The lens 1820 can bepositioned on the second MEMS device 1816 within the cavity. The cavitycan be sealed with the hermetic seal 1856. This structure can be puttogether with the fabricated array portion to form a second cavitytherebetween. The second cavity can be sealed with the hermetic seal1855. Inert gas or some other suitable material can fill either or boththe cavities. The via 1861 in the substrate 1895 can be extended throughthe window 1890 and the bonding material to allow electrical connectionto the ASIC 1830 and the two MEMS devices 1815, 1816. The resultingstructure, with the array 1810 and lens 1820 aligned, can form theimaging range finder 1800 of FIG. 18.

The imaging range finder 1800 of FIG. 18 can operate in any of theoperating modes of FIGS. 5A through 5F.

Imaging Range Finder with Dual Movable Lenses

FIG. 19 illustrates an imaging range finder having dual movable imaginglenses according to various examples. One lens can move along its x-axisand the other can move along its y-axis, thereby adjusting thecollimated light path to different angles according to the shiftedlenses' positions. This can advantageously allow the range finder todirect light at the target object so as to get the optimal detection ofthat object. In the example of FIG. 19, imaging range finder 1900 caninclude combined emitter-photodetector array 1910, similar to the array110 of FIG. 1. The range finder 1900 can also include imaging lenses1920, 1921, which can be the same or similar to the lens 1520 of FIG.15. The lenses 1920, 1921 can be coated with AR coating 1940.

The range finder 1900 can further include first MEMS device 1915 toconnect to the first lens 1920 to move the lens within a cavity. Thecavity can be formed by window 1990 and exit window 1985. The rangefinder 1900 can include second MEMS device 1915 to connect to the secondlens 1921 to move the lens within a second cavity. The second cavity canbe formed by the window 1990 and window 1991.

ASIC 1930 can support the array 1910 within a third cavity formed by theASIC and the window 1991. Inert gas 1945 or some other suitable materialcan fill any or all of the three cavities. ASIC 1930 can drive the array1910 and the two MEMS devices 1915, 1916.

The ASIC 1930 can have the same or similar configuration as the ASIC 930in FIG. 9. The ASIC 1930 can operate in a similar manner as well, exceptthe ASIC 1930 can drive the two MEMS devices 1915, 1916 to move thelenses 1920, 1921, rather than the prism 735 of FIG. 7.

The range finder 1900 can operate as follows. The ASIC 1930 can driveone or more of the emitters in the array 1910 to emit light. Asdescribed previously in FIG. 1, multiple emission patterns can be usedaccording to the system in which the range finder 1900 is to be used.The ASIC 1930 can also drive the lens 1920 to move along its x-axisand/or the lens 1921 to move along its y-axis or vice versa. The lenses1920, 1921 can receive and collimate the emitted light from the array1910. The amount that the lenses 1920, 1921 refract the emitted light asit passes through the lenses can depend on the position of the lenses.Accordingly, if either or both lenses 1920, 1921 move, they can outputthe collimated light toward a target object at a different angle. Thetarget object can reflect the light back to the lenses 1920, 1921. Thelenses 1920, 1921 can capture and focus the reflected light and cantransmit the focused light to one or more photodetectors in the array1910. The photodetectors driven by the ASIC 1930 can detect the focusedlight and transmit a detection signal to the ASIC 1930 or othercomponents for processing.

The light paths in the range finder 1900 can be adjusted because of lensmovement in the same or similar manner as depicted in FIGS. 16A and 16B.The net effect is that, because of the movable lenses 1920, 1921, theemitted light can be adjusted to contact a target object at adjustedpositions, which can advantageously allow the range finder flexibilityin directing light toward the object to get the optimal detection.

An exemplary fabrication process for the imaging range finder 1900 ofFIG. 19 can be similar to the fabrication in FIGS. 17A through 17F of amovable lens. For example, the fabrication process can start withcutting a transparent wafer to form exit window 1985 and a bonding waferto attach to the exit window. Portions of the wafer can be etched awayto expose the undersurface of the exit window 1985, forming a hollow forhousing the first lens 1920.

Imaging lenses 1920, 1921 can be formed using any of the methodspreviously described in FIG. 6B. AR coatings 1940 can be deposited ontothe formed lenses 1920, 1921 to coat the lenses. A transparent wafer canbe cut to form windows 1990, 1991. The first MEMS device 1915 can beprovided and bonded to the window 1990. Bonding material can bedeposited on the undersurface of the window 1990, forming a hollow forhousing the second lens 1921. The second MEMS device 1916 can beprovided and bonded to the window 1991. The undersurface of the window1991 can be sputter coated with the band-pass coating 1950. Bondingmaterial can be deposited on the undersurface of the window 1991,forming a hollow for housing the array 1910.

The ASIC 1930 can be provided and vias 1960 formed in the ASIC. Solderballs 1970 can be sputtered onto the undersurface of the ASIC 1930. Thearray 1910 can be provided and bonded to the ASIC 1930.

The fabricated exit window portion and the fabricated first MEMS portioncan be put together to form a cavity. The first lens 1920 can bepositioned on the first MEMS device 1915 within the cavity. The cavitycan be sealed with the hermetic seal 1957. This structure can be puttogether with the fabricated second window portion to form a secondcavity. The second lens 1921 can be positioned on the second MEMS device1915 within the second cavity. The second cavity can be sealed with thehermetic seal 1956. This structure can be put together with thefabricated array portion to form a third cavity. The third cavity can besealed with the hermetic seal 1955. Inert gas or some other suitablematerial can fill any or all of the three cavities. The via 1961 in theASIC 1930 can be extended through the windows 1990, 1991 and bondingmaterial to allow electrical connection to the MEMS devices 1915, 1916.The resulting structure, with the array 1910 and lenses 1920, 1921aligned, can form the imaging range finder 1900 of FIG. 19.

The imaging range finder 1900 of FIG. 19 can operate in any of theoperating modes of FIGS. 5A through 5F.

Imaging Range Finder with Multiple Imaging Lens

As described previously, because a surface of a target object is notgenerally perfectly smooth, light reflected off the object can scatteralong several paths, in addition to the reverse path of the light fromthe range finder. It can be beneficial to capture some of the scatteredlight to increase the amount of reflected light detected, therebyimproving the detection of the target object.

FIG. 20 illustrates a lens portion of an imaging range finder havingmultiple imaging lenses to capture scattered light according to variousexamples. In the example of FIG. 20, imaging range finder 2000 caninclude imaging lens 2020, which is similar to the lens 120 of FIG. 1,and window 2090 for holding the lens. The range finder 2000 can alsoinclude secondary imaging lenses 2021 adjacent to the lens 2020. Thesecondary lenses 2021 can have different focal lengths than the lens2020. The secondary lenses 2021 can capture the scattered light from theobject that could otherwise be lost. The secondary lenses 2021 can alsocompensate for aberrations resulting from the lens 2020 that result inlight loss at the edge of the emitter-photodetector array (not shown).This multiple lens combination can replace the lens portions in FIGS. 1,7, and 11, for example. The array portion (not shown) of the imagefinder 2000 can be the same or similar to any one of the array portionsshown in FIGS. 1, 7, 11, 15, 18, and 19, where a combinedemitter-photodetector array (not shown) can emit light via the lens 2020onto objects and detect light via the lens reflected back from theobject and where an ASIC (not shown) can drive the array.

The range finder 2000 can operate as follows. The ASIC can drive one ormore of the emitters in the array to emit light. As described previouslyin FIG. 1, multiple emission patterns can be used according to thesystem in which the range finder 2000 is to be used. The lens 2020 cancollimate and output the emitted light toward a target object. Thetarget object can reflect the light back to the lens 2020, withscattered light reflected to the secondary lenses 2021. The lenses 2020,2021 can capture and focus the reflected light and can transmit thefocused light to one or more photodetectors in the combinedemitter-photodetector array. The photodetectors in the combinedemitter-photodetector array driven by the ASIC can detect the focusedlight and transmit a detection signal to the ASIC or other componentsfor processing.

FIG. 21 depicts exemplary light paths for the range finder 2000. In theexample of FIG. 21, the reflected light path from object 2180 back tocombined emitter-photodetector array 2110 through the lenses 2120, 2121is depicted. Here, the object 2180 can reflect light 2117, in which mostof the light can be reflected back to the lens 2120 along the reversepath that the light traveled to the object and can be focused 2118 ontothe photodetectors of the array 2110. However, some of the reflected,scattered light 2112 can scatter away from the reverse path onto thesecondary lenses 2121. The secondary lenses 2121 can then focus thelight 2118 onto the photodetectors of the array 2110. Scattered lightthat would otherwise have been lost can be captured, thereby increasingthe amount of reflected light detected and, hence, improving thedetection of the target object.

During fabrication of the imaging range finder 2000, the lenses 2020,2021 and the window 2090 can be fabricated in the same or similar manneras described in FIGS. 6A and 6B, for example. The resulting structurecan be bonded to the array portion as described FIG. 6C, for example.

The imaging range finder 2000 of FIG. 20 can operate in any of theoperating modes of FIGS. 5A through 5F.

Imaging Range Finder Systems

One or more of the imaging range finders can operate in a system similaror identical to system 2200 shown in FIG. 22. System 2200 can includeinstructions stored in a non-transitory computer readable storagemedium, such as memory 2203 or storage device 2201, and executed byprocessor 2205. The instructions can also be stored and/or transportedwithin any non-transitory computer readable storage medium for use by orin connection with an instruction execution system, apparatus, ordevice, such as a computer-based system, processor-containing system, orother system that can fetch the instructions from the instructionexecution system, apparatus, or device and execute the instructions. Inthe context of this document, a “non-transitory computer readablestorage medium” can be any medium that can contain or store the programfor use by or in connection with the instruction execution system,apparatus, or device. The non-transitory computer readable storagemedium can include, but is not limited to, an electronic, magnetic,optical, electromagnetic, infrared, or semiconductor system, apparatusor device, a portable computer diskette (magnetic), a random accessmemory (RAM) (magnetic), a read-only memory (ROM) (magnetic), anerasable programmable read-only memory (EPROM) (magnetic), a portableoptical disc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flashmemory such as compact flash cards, secured digital cards, USB memorydevices, memory sticks, and the like.

The instructions can also be propagated within any transport medium foruse by or in connection with an instruction execution system, apparatus,or device, such as a computer-based system, processor-containing system,or other system that can fetch the instructions from the instructionexecution system, apparatus, or device and execute the instructions. Inthe context of this document, a “transport medium” can be any mediumthat can communicate, propagate or transport the program for use by orin connection with the instruction execution system, apparatus, ordevice. The transport medium can include, but is not limited to, anelectronic, magnetic, optical, electromagnetic or infrared wired orwireless propagation medium.

The system 2200 can further include imaging range finder 2209 coupled tothe processor 2205. The imaging range finder 2209 can be any of thosedescribed in FIGS. 1 through 21. The system 2200 can include touch panel2207 coupled to the processor 2205. Touch panel 2207 can have touchnodes capable of detecting an object touching or hovering over thepanel. The processor 2205 can process the outputs from the touch panel2207 to perform actions based on the touch or hover event.

It is to be understood that the system is not limited to the componentsand configuration of FIG. 22, but can include other or additionalcomponents in multiple configurations according to various examples.Additionally, the components of system 2200 can be included within asingle device, or can be distributed between multiple devices. In someexamples, the processor 2205 can be located within the touch panel 2207and/or the imaging range finder 2209.

FIG. 23 illustrates an exemplary mobile telephone 2300 that can includetouch panel 2324, display 2336, imaging range finder 2348, and othercomputing system blocks according to various examples.

FIG. 24 illustrates an exemplary digital media player 2400 that caninclude touch panel 2424, display 2436, imaging range finder 2448, andother computing system blocks according to various examples.

FIG. 25 illustrates an exemplary personal computer 2500 that can includetouch panel (trackpad) 2524, display 2536, imaging range finder 2548,and other computing system blocks according to various examples.

The mobile telephone, media player, and personal computer of FIGS. 23through 25 can increase capabilities and improve performance with animaging range finder according to various examples.

Imaging Range Finder Applications

An imaging range finder according to various examples can be used inseveral applications, for example: to scan a room to get accurate roommeasurements for interior design of the room; to map a space forinventory control, space planning, space navigation, and photo sharing;for 3D object scanning and pattern matching; as a navigation aid for thevisually-impaired to detect landmarks, stairs, low tolerances, and thelike; as a communication aid for the deaf to recognize and interpretsign language for a hearing user; for automatic foreground/backgroundsegmentation; for real-time motion capture and avatar generation; forphoto editing; for night vision; to see through opaque or cloudyenvironment, such as fog, smoke, haze; for computational imaging, suchas to change focus and illumination after acquiring images and video;for autofocus and flash metering; for same-space detection of anotherdevice; for two-way communication; for secure file transfers; to locatepeople or objects in a room; to capture remote sounds; and so on.

Therefore, according to the above, some examples of the disclosure aredirected to an imaging range finder comprising: an array formed of a setof emitters capable of emitting light and a set of photodetectorscapable of detecting light; an imaging lens formed proximate to and inoptical communication with the array and capable of collimating theemitted light from the emitters and focusing light received from anobject onto the photodetectors; and a driver circuit formed proximate tothe array and capable of driving the array. Additionally oralternatively to one or more of the examples disclosed above, the rangefinger can comprise a device coupled to at least one of the array or thelens to move the array or the lens, wherein the driver circuit iscoupled to the device to drive the device. Additionally or alternativelyto one or more of the examples disclosed above, the range finder cancomprise a movable prism formed between the lens and the array, whereinthe driver circuit is coupled to the prism to cause the prism to move.Additionally or alternatively to one or more of the examples disclosedabove, the range finder can comprise a second imaging lens formed inalignment with the imaging lens; and a device coupled to the imaginglens and the second imaging lens to move the lenses, wherein the drivercircuit is coupled to the device to drive the device. Additionally oralternatively to one or more of the examples disclosed above, the rangefinder can comprise a second imaging lens formed adjacent to the imaginglens to receive scattered light from the object and focus the scatteredlight onto the photodetectors. With respect to one or more of theexamples disclosed above, the range finder can be incorporated into atleast one of a mobile phone, a digital media player, or a personalcomputer.

Some examples of the disclosure are directed to a method of fabricatingan imaging range finder comprising: forming an imaging lens to receiveand output light; aligning with the lens an array of emitters to emitlight received at the lens and photodetectors to detect light outputtedfrom the lens; and positioning a driver circuit to drive the array.Additionally or alternatively to one or more of the examples disclosedabove, the method can comprise fixing the lens and the array in place.Additionally or alternatively to one or more of the examples disclosedabove, the method can comprise positioning a movable prism between thelens and the array; positioning a device adjacent to the prism to movethe prism; and coupling the driver circuit to the device to drive thedevice. Additionally or alternatively to one or more of the examplesdisclosed above, the method can comprise positioning a device adjacentthe array to move the array; and coupling the driver circuit to thedevice to drive the device. Additionally or alternatively to one or moreof the examples disclosed above, the method can comprise positioning adevice adjacent the lens to move the lens; and coupling the drivercircuit to the device to drive the device. Additionally or alternativelyto one or more of the examples disclosed above, the method can comprisepositioning at least one device proximate to the lens and the array tomove the lens and the array; and coupling the driver circuit to thedevice to drive the device. Additionally or alternatively to one or moreof the examples disclosed above, the method can comprise forming asecond imaging lens in alignment with the imaging lens; positioning adevice proximate to the two imaging lenses to move the lenses; andcoupling the driver circuit to the device to drive the device.Additionally or alternatively to one or more of the examples disclosedabove, the method can comprise forming at least one second imaging lensadjacent to the imaging lens, wherein the second imaging lens is capableof receiving and outputting scattered light. Additionally oralternatively to one or more of the examples disclosed above, the methodcan comprise combining at least one emitter and at least onephotodetector as a single node on the array. Additionally oralternatively to one or more of the examples disclosed above, the methodcan comprise forming at least one emitter and at least one photodetectoras separate nodes on the array.

Some examples of the disclosure are directed to an imaging range findersystem comprising: an imaging range finder formed to include an array ofnodes, each node formed to have at least a emitter or a photodetector,and an imaging lens formed proximate to the array and capable oftransmitting light from an emitter in one of the nodes toward an object,and transmitting light from the object to a photodetector in one of thenodes for detection; and a processor coupled to the range finder andcapable of processing a detection signal from the photodetector in theone node, the signal indicative of a characteristic of the object.Additionally or alternatively to one or more of the examples disclosedabove, the object characteristic includes at least one of a proximaterange of the object, a sound wave emanating from the object, data sentto the object, data received from the object, or presence of the objectin a predefined space. Additionally or alternatively to one or more ofthe examples disclosed above, at least one of the nodes combines anemitter and a photodetector.

Some examples of the disclosure are directed to a method of fabricatingan imaging range finder system comprising: forming an imaging rangefinder including an imaging lens formed to receive and output light, andan array formed to emit light from a set of emitters to the lens and todetect light outputted from the lens at a set of photodetectors; andcoupling a processor to the range finder to process a light detectionsignal from the photodetectors so as to find a range of an object fromthe range finder. Additionally or alternatively to one or more of theexamples disclosed above, the method can comprise forming the rangefinger to include a driver circuit positioned proximate to the array todrive the array. Additionally or alternatively to one or more of theexamples disclosed above, the driver circuit can be formed to drive atleast one of the emitters to emit light or the photodetectors to detectlight. Additionally or alternatively to one or more of the examplesdisclosed above, the processor can further be capable of recording asound emanating from the object, encoding data for sending via theemitted light to the object, decoding data received via the detectedlight from the object, or detecting to the object within a predefinedspace.

Although examples have been fully described with reference to theaccompanying drawings, it is to be noted that various changes andmodifications will become apparent to those skilled in the art. Suchchanges and modifications are to be understood as being included withinthe scope of the various examples as defined by the appended claims.

What is claimed is:
 1. An imaging range finder comprising: an integratedcircuit; an array comprised of emitters capable of emitting light andphotodetectors capable of detecting light; an imaging lens formedproximate to and in optical communication with the array; a drivercircuit included in the integrated circuit and capable of driving thearray; and a movable prism formed in a cavity; wherein one or more wallsof the cavity are formed by at least the integrated circuit, themoveable prism is positioned between the imaging lens and the array, andthe movable prism is capable of moving about a plurality of axes.
 2. Therange finder of claim 1, further comprising: a device coupled to atleast one of the array or the imaging lens to move the array or theimaging lens, wherein the driver circuit is coupled to the device todrive the device.
 3. The range finder of claim 1, wherein the drivercircuit is coupled to the movable prism to cause the movable prism tomove.
 4. The range finder of claim 1, further comprising: a secondimaging lens formed in alignment with the imaging lens; and a devicecoupled to the imaging lens and the second imaging lens to move theimaging lenses, wherein the driver circuit is coupled to the device todrive the device.
 5. The range finder of claim 1, further comprising: asecond imaging lens formed adjacent to the imaging lens to receivescattered light from the object and focus the scattered light onto thephotodetectors.
 6. The range finder of claim 1 incorporated into atleast one of a mobile telephone, a digital media player, or a portablecomputer.
 7. A method of fabricating an imaging range finder comprising:forming an imaging lens to receive and output light; aligning with theimaging lens an array of emitters to emit light received at the imaginglens and photodetectors to detect light outputted from the imaging lens;positioning an integrated circuit to support the array of emitters;including a driver circuit in the integrated circuit to drive the array;forming a cavity wherein one or more of the walls of the cavity areformed by at least the integrated circuit; positioning a movable prismin the cavity and between the imaging lens and array; and positioning adevice adjacent to the movable prism to move the movable prism about aplurality of axes.
 8. The method of claim 7, further comprising: fixingthe imaging lens and the array in place.
 9. The method of claim 7,further comprising: coupling the driver circuit to the device to drivethe device.
 10. The method of claim 7, further comprising: positioning adevice adjacent the array to move the array; and coupling the drivercircuit to the device to drive the device.
 11. The method of claim 7,further comprising: positioning a device adjacent the imaging lens tomove the imaging lens; and coupling the driver circuit to the device todrive the device.
 12. The method of claim 7, further comprising:positioning at least one device proximate to the imaging lens and thearray to move the imaging lens and the array; and coupling the drivercircuit to the device to drive the device.
 13. The method of claim 7,further comprising: forming a second imaging lens in alignment with theimaging lens; positioning at least one device proximate to the twoimaging lenses to move the two imaging lenses; and coupling the drivercircuit to the device to drive the device.
 14. The method of claim 7,further comprising: forming at least one second imaging lens adjacent tothe imaging lens, wherein the second imaging lens is capable ofreceiving and outputting scattered light.
 15. The method of claim 7,further comprising: combining at least one emitter and at least onephotodetector as a single node on the array.
 16. The method of claim 7,further comprising: forming at least one emitter and at least onephotodetector as separate nodes on the array.
 17. An imaging rangefinder system comprising: an imaging range finder formed to include anintegrated circuit, an array of nodes, each node formed to have at leastone of an emitter or a photodetector, and an imaging lens formedproximate to the array and capable of transmitting light from an emitterin one of the nodes toward an object, and transmitting light from theobject to a photodetector in one of the nodes for detection; and amovable prism formed in a cavity; wherein one or more walls of thecavity are formed by at least the integrated circuit, the moveable prismis positioned between the imaging lens and the array of nodes, and themoveable prism is capable of moving about a plurality of axes to adjusta path of light from an emitter; and a processor coupled to the rangefinder and capable of processing a detection signal from thephotodetector in the one node, the signal indicative of a characteristicof the object.
 18. The system of claim 17, wherein the objectcharacteristic includes at least one of a proximate range of the object,a sound wave emanating from the object, data sent to the object, datareceived from the object, or presence of the object in a predefinedspace.
 19. A method of fabricating an imaging range finder systemcomprising: forming an imaging range finder including an integratedcircuit, an imaging lens formed to receive and output light, an arrayformed to emit light from a set of emitters to the imaging lens and todetect light outputted from the imaging lens at a set of photodetectors,and a movable prism formed in a cavity, wherein one or more walls of thecavity are formed by at least the integrated circuit, and the moveableprism is positioned to move about a plurality of axes to adjust a pathof the emitted light; and coupling a processor to the imaging rangefinder to process a light detection signal from the set ofphotodetectors so as to find a range of an object from the range finder.20. The method of claim 19, further comprising: forming the range finderto include a driver circuit positioned proximate to the array to drivethe array.
 21. The method of claim 19, wherein the driver circuit isformed to drive at least one of the set of emitters to emit light or oneof the set of photodetectors to detect light.
 22. The method of claim19, wherein the processor is further capable of recording a soundemanating from the object, encoding data for sending via the emittedlight to the object, decoding data received via the detected light fromthe object, or detecting the object within a predefined space.
 23. Theimaging range finder of claim 1, wherein the moveable prism is furthercapable of moving about a first axis of the plurality of axes in aplurality of directions.
 24. The imaging range finder of claim 1,wherein: a first wall of the cavity is formed by at least by theintegrated circuit; a second wall is positioned opposite to the firstwall and formed at least by the imaging lens; and the first and secondwalls are coupled together at opposite ends of the cavity.
 25. Theimaging range finder of claim 24, wherein: the first and second wall areseparated by a first distance; the moveable prism has a length greaterthan the distance separating the first and second walls.